1. Going to be hard to get under 3000 with driver, unless you are about 100 pounds LOL. If you can get it that light, good on you, because that’s tough.
2. You already have the solid set up. I’d run it. Get your ducks in a row on start up and you’ll be fine.
3. I’d use the 4.30’s, but that’s me.
4. I use PTC for converters. Call them and let them pick the converter. I just did a 400 Chevy tunnel ram deal and used a PTC converter they spec’d. 8 inch case, 8 inch stator. It’s a converter they use for drag week. In this car it stalls at a bit over 5100 and drives better on the street than the junk 3800 converter that it replaced.
That’s what I’d do. Don’t skimp on gear or converter. That’s the two biggest combo killers there are.